A technology that transfers the data of video photographed by a web camera or the like in real time and displays the data on a display has recently been used in a wide range of fields. For example, there are not only video chats and surveillance cameras, which display photographed video as it is, but also a game in which a part of a body such as the head portion of a user or the like is photographed by a video camera, a predetermined region such as eyes, a mouth, a hand, or the like is extracted and replaced with another image, and the result is displayed on a display (Patent Literature 1, for example).